Oh Dear ! not much help here im afraid.
i hate to admit it but i am totally anal with regards the upkeep of my equipment.... slightest hint of rain, snow, or windy dusty environments and its back in the bag

'No longer are the pleasures of Home Movie Making limited to those with ample funds. Now the man and woman of moderate means can join the sport'..... Kodak catalogue 1933

Thanks guys. I'm there for 6days. Anticipating about 2-3 hours filming a day, batteries are supposed to last 420min so hoping 7 batts will be enough.
My c100mk2 has a fan in it, im not sure wether its better to switch it off to stop stand getting in or keep it on to keep the camera cool :/

Having kids, I do a fair amount of filming on the beach. From experience, unless you've got weather sealed gear, expect sand to get into everything. I destroyed a cheap M43 lens by getting sand in the zoom mechanism - and I was pretty careful! I wouldn't take anything to a desert unless a) it was weather sealed or b) I expected it to be damaged beyond repair.